JP2005028228A

JP2005028228A - Gas treating method

Info

Publication number: JP2005028228A
Application number: JP2003193611A
Authority: JP
Inventors: Takashi Yamashita; 孝山下; Yukio Fukushima; 幸生福島; Noriharu Sasaki; 典令佐々木; Masayoshi Sakuma; 正芳佐久間; Seiji Tsuchida; 清次土田
Original assignee: Hitachi Plant Technologies Ltd
Current assignee: Hitachi Plant Technologies Ltd
Priority date: 2003-07-08
Filing date: 2003-07-08
Publication date: 2005-02-03

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for treating a gas with activated carbon, in which the amount of steam to be supplied can be reduced and the optimum time to exchange an adsorbing material can be recognized. <P>SOLUTION: An apparatus 10 for treating the gas is provided with two adsorption columns 12a, 12b packed with activated carbon 14a, 14b. Exhaust gas is introduced into one of the columns 12a, 12b. Withdrawing ducts 42x, 42y are connected to the upper part and the middle part of each of the columns 12a, 12b, respectively. Another withdrawing duct 42z is connected to a guide duct 22. Sensor parts 44x-44z are arranged on the ducts 42x-42z respectively so that the concentration of a harmful component of the gas flowing in each of the ducts 42x-42z is measured. When the value measured by the part 44y reaches the prescribed value, the column into which the exhaust gas is introduced is switched between the columns 12a and 12b. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

【０００１】
【発明の属する技術分野】
本発明はガス処理方法に係り、特に医薬品や半導体等を製造する製造工場において、人体に有害な有機溶剤成分や悪臭成分を排ガスから除去するガス処理方法に関する。
【０００２】
【従来の技術】
医薬品の製造工場では、有機溶剤の濃縮や抽出を行う工程があり、これらの工程から排出された排ガスには有機溶剤成分や悪臭成分（以下、まとめて有害成分と称す）が含まれることがある。このため、医薬品の製造工場では、排ガスから有害成分を除去するガス処理設備が必要になる。
【０００３】
排ガスの処理量が小さい場合、ガス処理設備は、活性炭が充填された一塔の吸着塔から成り、排ガスはこの吸着塔に導入され、排ガス中の有害成分が活性炭に吸着除去される。このガス処理設備では、活性炭が破過すると、活性炭を破棄して新たな活性炭と交換したり、破過した活性炭を再生メーカに引き渡してオフサイトで再生して交換したりしている。
【０００４】
一方、排ガスの処理容量が大きい場合は、複数の吸着塔が設けられ、この複数の吸着塔の少なくとも一塔にガスが導入され、ガス中の有害成分が吸着除去される。このガス処理設備では、ガスを導入する吸着塔を定期的に切り替えるとともに、有害成分を吸着した活性炭の再生処理（すなわち、有害成分の脱着処理）を行うことによって、排ガスの処理を連続して行うことができる。
【０００５】
複数の吸着塔から成るガス処理設備は、活性炭の脱着方法によって蒸気再生式と乾式再生式とに分けられる。乾式再生式は、ヒータで加熱した脱着用キャリアガスを吸着塔に通過させて活性炭を加熱したり、活性炭内に設置したヒータによって活性炭を直接加熱したりすることによって、活性炭の再生を行う方式である。この方式は、メンテナンスが容易である反面、脱着効率が低いという欠点がある。
【０００６】
これに対して、蒸気再生式は、吸着塔内に蒸気を通過させて活性炭を均一に加熱し、脱着を行う方式である。この方式は、脱着効率が非常に高い反面、蒸気使用量が多いという問題や、蒸気を供給した際に生じるドレンの排水処理が必要になるという問題がある。
【０００７】
特許文献１には、蒸気の供給前に吸着塔内を減圧するガス処理設備が記載されている。このガス処理設備によれば、少量の蒸気を導入するだけで活性炭を再生することができ、蒸気使用量及び排水処理量を低減することができる。
【０００８】
【特許文献１】
特開平５−８４４１７号公報
【０００９】
【発明が解決しようとする課題】
しかしながら、従来のガス処理設備は、吸着塔の切り替えが固定タイマーによるシーケンス制御であるため、余分な蒸気を多量に供給するおそれがあった。例えば、有害成分の濃度が低い排ガスを吸着塔に導入した場合、吸着塔を定期的に切り替えると、活性炭に有害成分が十分に吸着してない状態で吸着塔が切り替えられる。このため、有害成分が十分に吸着してない活性炭に蒸気が供給されることになり、脱着処理に寄与しない過剰な蒸気が多くなる。したがって、従来のガス処理設備は、無駄な蒸気供給量が多くなり、排水処理負荷が増加するという問題があった。
【００１０】
さらに、従来のガス処理設備は、活性炭を交換する時期が正確に分からないため、十分な吸着性能を有する活性炭を交換することがあった。
【００１１】
本発明はこのような事情に鑑みて成されたもので、蒸気供給量を低減することができるとともに、吸着材の最適な交換時期を知ることのできるガス処理方法を提供することを目的とする。
【００１２】
【課題を解決するための手段】
請求項１に記載の発明は前記目的を達成するために、吸着材が収納された複数の吸着塔の少なくとも一つにガスを通過させることによって前記ガスに含まれる悪臭成分及び／又は溶剤成分を前記吸着材に吸着させるとともに、前記ガスを通過させる吸着塔を切り替え、前記吸着材に吸着した前記悪臭成分及び／又は前記溶剤成分を脱着させるガス処理方法において、前記吸着材で吸着処理したガス、又は前記吸着材で吸着処理しているガスに含まれる前記悪臭成分の濃度及び／又は前記溶剤成分の濃度を測定し、該濃度の測定値に基づいて、前記ガスを通過させる吸着塔を切り替えることを特徴としている。
【００１３】
請求項１に記載の発明によれば、吸着処理後、又は吸着処理中のガスに含まれる悪臭成分の濃度及び／又は溶剤成分の濃度に基づいて吸着塔を切り替えるので、悪臭成分や溶剤成分が吸着材に十分に吸着した状態で脱着処理が開始される。したがって、脱着処理に寄与しない余分な蒸気量を減少させることができ、脱着処理に伴って必要となる排水処理量を減少させることができる。
【００１４】
また、請求項１に記載の発明によれば、悪臭成分や溶剤成分を吸着材に十分に吸着させてから吸着塔を切り替えるので、吸着処理の時間が長くなり、脱着処理の頻度が減少する。したがって、吸着効率を向上させることができるとともに、吸着材の負荷が減少して、吸着材の寿命が延長される。
【００１５】
請求項２に記載の発明は前記目的を達成するために、吸着材が収納された複数の吸着塔の少なくとも一つにガスを通過させることによって前記ガスに含まれる悪臭成分及び／又は溶剤成分を前記吸着材に吸着させるとともに、前記ガスを通過させる吸着塔を切り替え、前記吸着材に吸着した前記悪臭成分及び／又は前記溶剤成分を脱着させるガス処理方法において、前記吸着材で吸着処理したガス、又は前記吸着材で吸着処理しているガスに含まれる前記悪臭成分の濃度及び／又は前記溶剤成分の濃度を測定し、該濃度の測定値が所定値に達した際に、前記吸着塔から排出されるガスの流路を切り替え、該ガスを補助用の吸着塔に通過させることを特徴としている。
【００１６】
請求項２に記載の発明によれば、吸着塔からのガスに含まれる悪臭成分の濃度及び／又は溶剤成分の濃度が所定値に達した際に、ガスの流路を切り替えて補助用の吸着塔にガスを通過させるので、濃度が所定値に達したガスは補助用の吸着塔に導入され、悪臭成分や溶剤成分が吸着除去される。したがって、悪臭成分や溶剤成分の濃度が所定値に達したガスが放出されることを防止できる。
【００１７】
請求項３に記載の発明は前記目的を達成するために、吸着材が収納された複数の吸着塔の少なくとも一つにガスを通過させることによって前記ガスに含まれる悪臭成分及び／又は溶剤成分を前記吸着材に吸着させるとともに、前記ガスを通過させる吸着塔を切り替え、前記吸着材に吸着した前記悪臭成分及び／又は前記溶剤成分を脱着させるガス処理方法において、前記吸着材で吸着処理する前のガスに含まれる前記悪臭成分の濃度及び／又は前記溶剤成分の濃度を測定し、該吸着処理前の濃度に基づいて、前記吸着材で吸着処理する時間を演算し、該演算値に基づいて、前記ガスを通過させる吸着塔を切り替えることを特徴としている。
【００１８】
請求項３に記載の発明によれば、吸着処理前のガスに含まれる悪臭成分の濃度及び／又は溶剤成分の濃度に基づいて、吸着処理する時間を演算して吸着塔を切り替えるので、悪臭成分及び／又は溶剤成分が吸着材に十分に吸着した状態で、吸着塔を切り替えることができる。
【００１９】
請求項４に記載の発明は請求項３の発明において、前記吸着材で吸着処理したガス、又は前記吸着材で吸着処理しているガスに含まれる前記悪臭成分の濃度及び／又は前記溶剤成分の濃度を測定し、該吸着処理後又は吸着処理中の濃度に基づいて、前記演算値を補正することを特徴としている。したがって、請求項４に記載の発明によれば、吸着材の吸着状況に応じて演算値を補正するので、吸着処理するのに最適な時間を精度良く求めることができる。
【００２０】
【発明の実施の形態】
以下、添付図面に従って本発明に係るガス処理方法の好ましい実施の形態について説明する。
【００２１】
図１は、本発明に係るガス処理方法が適用されたガス処理設備の第１の実施形態を模式的に示す構成図である。
【００２２】
図１に示すように、ガス処理装置１０は、二塔の吸着塔１２ａ、１２ｂを備える。各吸着塔１２ａ、１２ｂの内部には支持板１６、１６が設けられ、この支持板１６、１６の上に活性炭１４ａ、１４ｂが充填される。活性炭１４ａ、１４ｂは、繊維状、ハニカム状、ペレット状などが任意に選択される。なお、支持板１６は、通気性及び通水性を有する部材、例えばパンチングプレート等が使用される。
【００２３】
各吸着塔１２ａ、１２ｂの上部にはそれぞれ、導入ダクト１８、１８が接続される。導入ダクト１８、１８の先端は製造設備に接続されており、この製造設備から排出された排ガスが導入ダクト１８、１８を介して吸着塔１２ａ、１２ｂに導入される。導入ダクト１８、１８には各吸着塔１２ａ、１２ｂの導入口部分に、ダンパ２０ａ、２０ｂが配設される。このダンパ２０ａ、２０ｂを開閉制御することによって、排ガスを導入する吸着塔１２ａ、１２ｂが切り替えられる。
【００２４】
吸着塔１２ａ、１２ｂに導入されたガスは、ガス中の有害成分（悪臭成分及び／又は溶剤成分）が活性炭１４ａ、１４ｂによって吸着される。そして、吸着処理後の処理ガスが、各吸着塔１２ａ、１２ｂの下部に接続された導出ダクト２２、２２から導出される。導出ダクト２２、２２は外気に通じており、吸着塔１２ａ、１２ｂから導出されたガスは導出ダクト２２、２２を介して外気に放出される。導出ダクト２２、２２の吸着塔１２ａ、１２ｂの導出口部分には、ダンパ２４ａ、２４ｂが配設される。このダンパ２４ａ、２４ｂはダンパ２０ａ、２０ｂとともに開閉制御される。
【００２５】
吸着塔１２ａ、１２ｂの下部にはそれぞれ蒸気供給管２６、２６が接続されている。蒸気供給管２６、２６の先端は蒸気発生源に接続されており、この蒸気発生源から発生した蒸気が蒸気供給管２６、２６を介して吸着塔１２ａ、１２ｂに供給される。なお、蒸気発生源として製造設備で発生した蒸気を用いてもよい。
【００２６】
蒸気供給管２６、２６の、吸着塔１２ａ、１２ｂの入口側部分にはそれぞれ、バルブ２８ａ、２８ｂが配設される。このバルブ２８ａ、２８ｂを開閉制御することによって、吸着塔１２ａ、１２ｂの一方に蒸気が供給される。吸着塔１２ａ、１２ｂに供給された蒸気は、各吸着塔１２ａ、１２ｂの上部に接続された蒸気排出管３０、３０から排出されるか、或いは、凝縮してドレンとなった後に、各吸着塔１２ａ、１２ｂの下部に接続したドレン管３２、３２から排出される。
【００２７】
蒸気排出管３０、３０の先端はコンデンサに接続されており、このコンデンサによって、蒸気に含まれる有用ガスが回収される。一方、ドレン管３２、３２の先端は排水処理設備に接続されており、ドレンに含まれる有害成分が除去される。なお、蒸気排出管３０、３０の各吸着塔１２ａ、１２ｂの出口側にはそれぞれバルブ３４ａ、３４ｂが配設される。また、ドレン管３２、３２の各吸着塔１２ａ、１２ｂの出口側にはそれぞれバルブ３６ａ、３６ｂが配設される。
【００２８】
ところで、ガス処理設備１０は、ガスに含まれる有害成分の濃度を三カ所で測定するように構成される。すなわち、ガス処理設備１０は、ガスを引き抜く吸引ポンプ４０と、この吸引ポンプ４０の吸引口に接続された第１〜第３の引き抜きダクト４２ｘ、４２ｙ、４２ｚと、各引き抜きダクト４２ｘ、４２ｙ、４２ｚに配設されたセンサ部４４ｘ、４４ｙ、４４ｚと、を備えている。
【００２９】
各センサ部４４ｘ〜４４ｚは、ガス中の悪臭成分の濃度を検出する匂いセンサ（不図示）と、ガス中の溶剤成分の濃度を検出する溶剤センサ（不図示）とで構成され、二つのセンサが並列に接続されている。したがって、各センサ部４４ｘ〜４４ｚによって、各引き抜きダクト４２ｘ〜４２ｚを流れるガス中の悪臭成分の濃度と溶剤成分の濃度とを同時に測定することができる。
【００３０】
第１の引き抜きダクト４２ｘは、各吸着塔１２ａ、１２ｂの、活性炭１４ａ、１４ｂの上方に接続されている。したがって、吸引ポンプ４０を駆動することによって、吸着処理前のガスが引き抜かれる。また、第１の引き抜きダクト４２ｘには、バルブ４６ａ、４６ｂが設けられる。ガスを引き抜く際には、バルブ４６ａ、４６ｂの一方を開くことによって、吸着塔１２ａまたは１２ｂのガスが引き抜かれる。なお、第１の引き抜きダクト４２ｘを導入ダクト１８に接続し、導入ダクト１８を流れるガスを引き抜いてもよい。
【００３１】
第２の引き抜きダクト４２ｙは、各吸着塔１２ａ、１２ｂの、活性炭１４ａ、１４ｂの位置に接続されている。したがって、活性炭１４ａ、１４ｂで吸着処理しているガスが引き抜かれる。また、第２の引き抜きダクト４２ｙには、バルブ４８ａ、４８ｂが設けられる。ガスを引き抜く際は、このバルブ４８ａ、４８ｂの一方を開くことによって、吸着塔１２ａまたは１２ｂからガスが引き抜かれる。なお、第２の引き抜きダクト４２ｙの接続位置は、活性炭１４ａ、１４ｂの上端から接続位置までの距離Ｌ_１が、活性炭１４ａ、１４ｂの全高さＬ_０の７０〜９０％になるように設定することが好ましい。
【００３２】
第３の引き抜きダクト４２ｚは、導出ダクト２２に接続される。したがって、導出ダクト２２を流れる処理ガスの一部が第３の引き抜きダクト４２ｚに引き抜かれる。また、第３の引き抜きダクト４２ｚにはバルブ５０が配設され、このバルブ５０を開くことによって処理ガスが引き抜かれ、吸引ポンプ４０に吸引される。
【００３３】
吸引ポンプ４０の吐出口には返送ダクト５２が接続され、この返送ダクト５２は導入ダクト１８に接続される。返送ダクト５２には、バルブ５４が配設されており、このバルブ５４を開くことによって、吸引ポンプ４０から送気されたガスが返送ダクト５２を介して導入ダクト１８に返送される。したがって、第１〜第３の引き抜きダクト４２ｘ〜４２ｚから引き抜かれたガスは、吸着塔１２ａ、１２ｂに再度導入され、有害成分が吸着除去される。
【００３４】
上述した各ダンパ２０ａ、２０ｂ、２４ａ、２４ｂ、及び各バルブ２８ａ、２８ｂ、３４ａ、３４ｂ、３６ａ、３６ｂ、４６ａ、４６ｂ、４８ａ、４８ｂ、５０、５４は、制御装置５６に電気的に接続されており、制御装置５６によって開閉される。
【００３５】
制御装置５６は、ダンパ２０ａ、２０ｂ、２４ａ、２４ｂを開閉させることによって、吸着塔１２ａ、１２ｂの一方に排ガスを通気して吸着処理を行う。例えば、ダンパ２０ａ、２４ａを開くとともにダンパ２０ｂ、２４ｂを閉じることによって、排ガスを吸着塔１２ａに通気し、排ガスに含まれる有害成分を活性炭１４ａに吸着させる。或いは、ダンパ２０ａ、２４ａを閉じるとともにダンパ２０ｂ、２４ｂを開くことによって、排ガスを吸着塔１２ｂに通気し、排ガスに含まれる有害成分を活性炭１４ｂに吸着させる。
【００３６】
また、制御装置５６は、バルブ２８ａ、２８ｂ、３４ａ、３４ｂ、３６ａ、３６ｂを開閉させることによって、吸着塔１２ａ、１２ｂの一方に蒸気を通気して脱着処理を行う。例えば、バルブ２８ａ、３４ａ、３６ａを閉じるとともに、バルブ２８ｂ、３４ｂ、３６ｂを開くことによって、吸着塔１２ｂに蒸気を通気し、活性炭１４ｂに吸着した有害成分を脱着させる。或いは、バルブ２８ａ、３４ａ、３６ａを開くとともに、バルブ２８ｂ、３４ｂ、３６ｂを閉じることによって、吸着塔１２ａに蒸気を通気し、活性炭１４ａに吸着した有害成分を脱着させる。なお、脱着処理は、吸着処理を行っていない吸着塔１２ａ、１２ｂで行われる。脱着処理を終了した後は、バルブ２８ａ或いは２８ｂを閉じて、吸着塔１２ａ、１２ｂの内部を乾燥させた状態で待機させる。
【００３７】
また、制御装置５６は、吸引ポンプ４０を駆動制御するとともにバルブ４６ａ、４６ｂ、４８ａ、４８ｂ、５０、５４を開閉制御することによって、第１〜第３の引き抜きダクト４２ｘ〜４２ｚからガスを引き抜く。その際、吸着処理を行っている吸着塔１２ａ或いは１２ｂからガスを引き抜くように、バルブ４６ａ、４６ｂ、４８ａ、４８ｂを開閉させる。そして、引き抜きダクト４２ｘ〜４２ｚに配設したセンサ部４４ｘ〜４４ｚによってガス中の有害成分の濃度を測定し、その測定値に基づいて、上述したバルブ２０ａ、２０ｂ、２４ａ、２４ｂを開閉させ、吸着処理を行う吸着塔１２ａ、１２ｂを切り替える。
【００３８】
次に、第１の実施形態のガス処理設備１０の制御方法について説明する。
【００３９】
ガス処理設備１０では、一方の吸着塔１２ａまたは１２ｂに排ガスを通気して吸着処理を行うとともに、他方の吸着塔１２ｂまたは１２ａで脱着処理を行う。そして、第２の引き抜きダクト４２ｙに設けたセンサ部４４ｙの測定値が所定値に達した際に、吸着処理を行う吸着塔１２ａ、１２ｂを切り替えるように制御する。ここで、所定値とは、法規によって定められた値、或いはそれよりも低い値に設定され、悪臭成分の濃度と、溶剤成分の濃度の両方に対してそれぞれ設定される。そして、悪臭成分の濃度と溶剤成分の濃度のどちらか一方が所定値に達した際に切替制御が行われる。
【００４０】
吸着塔１２ａで吸着処理を行っていた際にセンサ部４４ｙの測定値が所定値に達した場合、バルブ２０ａ、２４ａを閉じてバルブ２０ｂ、２４ａを開くことによって、吸着塔１２ａに通気していた排ガスを吸着塔１２ｂに通気させる。同様に、吸着塔１２ｂで吸着処理を行っていた際にセンサ部４４ｙの測定値が所定値に達した場合は、バルブ２０ｂ、２４ｂを閉じてバルブ２０ａ、２４ｂを開くことによって、吸着塔１２ｂに通気していた排ガスを吸着塔１２ａに通気させる。
【００４１】
次に上記の如く構成されたガス処理設備１０の作用について説明する。
【００４２】
吸着塔１２ａまたは１２ｂで吸着処理を行うと、その吸着塔１２ａまたは１２ｂから導出される処理ガスは、経過時間に伴って有害ガスの濃度が徐々に増加する。すなわち、吸着処理の初期には、活性炭１４ａ、１４ｂが十分な吸着能力を保持しているので、有害成分は確実に活性炭１４ａ、１４ｂに吸着される。したがって、吸着塔１２ａ、１２ｂから排出される処理ガスに含まれる有害成分の濃度は非常に低い。しかし、吸着処理を行うに連れて、活性炭１４ａ、１４ｂの吸着能力が徐々に低下するため、処理ガス中の有害成分の濃度は徐々に上昇する。そして、活性炭１４ａ、１４ｂが破過すると、有害成分の濃度が急激に上昇し、吸着処理前の有害成分の濃度に近い値になる。これを防止するため、従来は、活性炭１４ａ、１４ｂが破過する前に、吸着塔１２ａ、１２ｂを定期的に切り替えて吸着処理を行っていた。このため、活性炭１４ａ、１４ｂが有害成分を十分に吸着してない状態で吸着塔１２ａ、１２ｂを切り替えることになり、脱着処理時に無駄な蒸気が多くなるという問題があった。
【００４３】
これに対して、本実施の形態は、センサ部４４ｙの測定値が所定値に達した際に吸着塔１２ａ、１２ｂを切り替えている。したがって、活性炭１４ａ、１４ｂに有害成分が十分に吸着した状態で吸着塔１２ａ、１２ｂを切り替えるので、脱着処理を行った際の、脱着処理に寄与しない無駄な蒸気の量を減らすことができる。
【００４４】
また、本実施の形態では、吸着処理中のガスを引き抜いて有害成分の濃度を測定しているので、有害成分の濃度が所定値に達したガスが放出されることを防止できる。すなわち、有害成分の濃度が所定値に達した際、引き抜きダクト４２ｙの接続位置よりも上側の活性炭１４ａ、１４ｂは破過に近い状態になっているが、接続位置よりも下側の活性炭１４ａ、１４ｂは十分な吸着能力を保持している。したがって、接続位置において有害成分の濃度が所定値に達したガスは、接続位置よりも下側の活性炭１４ａ、１４ｂによって有害成分が吸着除去されるので、活性炭１４ａ、１４ｂを通過した後のガスに含まれる有害成分の濃度は、所定値よりも低くなる。これにより、有害成分の濃度が所定値に達したガスが放出されることを防止できる。
【００４５】
さらに、本実施の形態は、活性炭１４ａ、１４ｂに有害成分を十分に吸着してから吸着塔１２ａ、１２ｂを切り替えるので、吸着処理を行う時間が長くなり、吸着処理の効率を向上させることができる。また、脱着処理の頻度が減少するので、活性炭１４ａ、１４ｂの負荷が減少し、活性炭１４ａ、１４ｂの寿命を延長することができる。
【００４６】
また、本実施の形態は、センサ部４４ｙの測定値が所定値に達するまでの時間、すなわち、活性炭１４ａ、１４ｂが破過する直前までの時間（以下、吸着処理時間という）が分かるので、活性炭１４ａ、１４ｂの交換時期を予測することができる。
【００４７】
なお、上述した第１の実施形態において、センサ部４４ｘの測定値は、吸着処理する時間を演算するのに利用するとよい。そして、この演算した時間に基づいて生産工程を管理したり、演算した時間の前後だけガスを引き抜いて濃度を測定するようにしてもよい。
【００４８】
さらに、上述した第２の実施形態において、センサ部４４ｚの測定値は、異常の検出に利用するとよい。例えば、センサ部４４ｚの測定値が、前述した所定値に達した際に異常事態が発生したとして、作業者に警告したり、装置を停止したりするとよい。
【００４９】
図２は、本発明に係るガス処理設備の第２の実施形態を模式的に示す構成図である。
【００５０】
図２に示すように、第２の実施形態のガス処理設備は、導出ダクト２２の先端部にダンパ６０が配設されており、このダンパ６０の上流側と下流側にバイパスライン６２が接続されている。バイパスライン６２には、ダンパ６４、及び補助用吸着塔６６が配設されている。補助用吸着塔６６は、吸着塔１２ａ、１２ｂと同様に構成され、内部に活性炭６８が充填されている。ただし、補助用吸着塔６６は、吸着塔１２ａ、１２ｂよりも小さな容量で構成される。
【００５１】
上記の如く構成された第２の実施形態では、吸着塔１２ａ或いは１２ｂで吸着処理を行う際、ダンパ６０が開かれ、且つダンパ６４が閉じられる。そして、センサ部４４ｚの測定値が所定値に達した際に、吸着処理を行う吸着塔１２ａ、１２ｂが切り替えられるとともに、ダンパ６０が閉じられ、且つダンパ６４が開かれる。これにより、導出ダクト２２を流れる処理ガスはバイパスライン６２に流れて補助用吸着塔６６に導入される。補助用吸着塔６６に導入された処理ガスは、有害成分が活性炭６８に吸着される。したがって、補助用吸着塔６６から排出される処理ガスは、有害成分の濃度が所定値よりも低くなっている。これにより、吸着塔１２ａ、１２ｂの切替時に、有害成分の濃度が所定値に達したガスが放出されることを防止できる。
【００５２】
なお、処理ガスを補助用吸着塔６６に通気する時間は、数分或いは数十秒程度でよい。或いは、センサ部４４ｚの測定値が十分に低下したことを確認した後に、補助用吸着塔６６への通気を停止してもよい。
【００５３】
また、処理ガスの通気を停止した補助用吸着塔６６に蒸気を供給し、脱着処理を行うようにしてもよい。
【００５４】
さらに、上述した第２の実施形態では、センサ部４４ｚの測定値に基づいて吸着塔１２ａ、１２ｂを切り替えたが、これに限定するものではなく、第１の実施形態と同様にセンサ部４４ｙの測定値に基づいて切り替えてもよい。この場合、有害成分の濃度が所定値に達したガスは、引き抜きダクト４２ｙの接続位置よりも下側の活性炭１４ａ、１４ｂと、補助用吸着塔６６の活性炭６８とによって吸着処理されるので、有害成分の濃度が高い処理ガスが放出されることを防止できる。
【００５５】
図３は、第３の実施形態のガス処理設備の制御系統図である。なお、第３の実施形態のガス処理設備は、図１に示した第１の実施形態のガス処理設備１０と同様に構成される。
【００５６】
図３に示すように、制御装置５６は、データベース７０、演算処理部７２、ダンパ・バルブ制御部７４を備える。演算処理部７２には、センサ部４４ｘ、４４ｙの測定値のデータと、製造設備の制御部７６から生産情報が入力される。生産情報としては、例えば、製造設備で使用したガスの種類や量、製造設備の稼働時間や稼働ライン数、生産物の種類や生産量等が入力される。
【００５７】
演算処理部７２は、センサ部４４ｘ、４４ｙの測定値や生産情報と、データベース７０に記憶された演算方法に基づいて、吸着処理時間（図１の活性炭１４ａ、１４ｂが破過する直前までの時間）を演算する。この演算に関わったデータ（測定値、生産情報、演算回数等のデータ）は、データベース７０に記憶され、ニューロネットワークが構築される。これにより、演算処理回数が増えるに連れて、吸着処理時間の演算の精度を高めることができる。
【００５８】
演算処理部７２で演算した結果を示すデータはダンパ・バルブ制御部７４に出力される。ダンパ・バルブ制御部７４はこの演算結果に基づいてダンパ２０ａ、２０ｂ、２４ａ、２４ｂ及びバルブ２８ａ、２８ｂ、３４ａ、３４ｂ、３６ａ、３６ｂ、４６ａ、４６ｂ、４８ａ、４８ｂ、５０、５４を開閉させる。すなわち、演算された吸着処理時間で、吸着塔１２ａ、１２ｂを切り替える。
【００５９】
次に上記の如く構成された第３の実施形態のガス処理設備の作用について説明する。
【００６０】
吸着塔１２ａ、１２ｂに導入される排ガスの状態、すなわち、排ガスの流量や排ガスに含まれる有害成分の種類や濃度等は常に一定であるとは限らないため、活性炭１４ａ、１４ｂが破過する直前までの吸着処理時間も常に一定ではなく、大きく変化するおそれがある。また、排ガスの状態が一定であった場合でも、脱着処理を繰り返すに連れて、脱着処理後の活性炭１４ａ、１４ｂは吸着性能が徐々に低下するので、吸着処理時間は徐々に短くなるという問題がある。
【００６１】
このような問題を解決するため、第３の実施形態では、センサ部４４ｘの測定値や生産情報を演算処理部７２に入力することによって、吸着塔１２ａ、１２ｂに導入する前の排ガスの状態を正確に把握し、これに基づいて吸着処理時間を演算している。したがって、排ガスの状態が変化した場合であっても、常に最適なタイミングで、すなわち、吸着材１４ａ、１４ｂが有害成分を十分に吸着したタイミングで吸着塔１２ａ、１２ｂを切り替えることができる。
【００６２】
また、第３の実施形態では、センサ部４４ｙの測定値を入力しているので、吸着材１４ａ、１４ｂの実際の吸着能力を知ることができ、これに基づいて演算結果を補正できるので、より正確に吸着処理時間を求めることができる。
【００６３】
さらに、第３の実施形態では、吸着処理した回数毎のデータをデータベース７０に蓄積することによって、徐々に短くなる吸着処理時間を精度良く求めることができる。したがって、吸着処理や脱着処理の回数が多い吸着材においても、常に最適な吸着処理時間を演算することができる。また、この演算結果から、活性炭１４ａ、１４ｂの最適な交換時期を予測することができる。
【００６４】
なお、上述した第１〜３の実施形態は、二つの吸着塔１２ａ、１２ｂを用いたが、三つ以上の吸着塔を用いてもよい。その際、少なくとも一つの吸着塔で吸着処理を行っていればよい。
【００６５】
また、上述した実施形態は、吸着材として活性炭を使用したが、吸着材の種類はこれに限定するものではなく、例えば活性アルミナ、シリカゲル、ゼオライト等の吸着材を、吸着する対象物に応じて選択してもよい。
【００６６】
さらに、上述した実施形態は、センサ部４４ｘ〜４４ｚとして、悪臭成分の濃度を測定する匂いセンサと、溶剤成分の濃度を測定する溶剤センサを設けたが、悪臭成分と溶剤成分のどちらか一方の成分のみを対象として除去する場合には、その対象となる成分用のセンサのみを設ければよい。
【００６７】
【発明の効果】
以上説明したように本発明に係るガス処理方法によれば、吸着処理後又は吸着処理中のガスに含まれる悪臭成分の濃度及び／又は溶剤成分の濃度に基づいて、吸着処理を行う吸着塔を切り替えるようにしたので、吸着材に有害成分を十分に吸着させた状態で脱着処理を開始することができる。これにより、脱着処理に寄与しない無駄な蒸気量を減少させることができ、結果として蒸気供給量及び排水処理量を減少させることができる。
【００６８】
また、本発明に係るガス処理方法によれば、吸着塔を切り替える際に、ガスを補助用吸着塔に通気するようにしたので、濃度が所定値に達したガスが放出されることを防止できる。
【００６９】
さらに、本発明に係るガス処理方法によれば、吸着処理前のガスに含まれる悪臭成分の濃度及び／又は溶剤成分の濃度に基づいて吸着処理時間を演算し、吸着塔を切り替えるので、最適なタイミングで吸着塔を切り替えることができる。
【図面の簡単な説明】
【図１】本発明に係るガス処理方法が適用されたガス処理設備の第１の実施形態を模式的に示す構成図
【図２】第２の実施形態のガス処理設備の特徴部分を模式的に示す構成図
【図３】第３の実施形態のガス処理設備の制御系統図
【符号の説明】
１０…ガス処理設備、１２ａ、１２ｂ…吸着塔、１４ａ、１４ｂ…活性炭、１８…導入ダクト、２２…導出ダクト、２０ａ、２０ｂ、２４ａ、２４ｂ…ダンパ、２６…蒸気供給管、３０…蒸気排出管、３２…ドレン管、２８ａ、２８ｂ、３４ａ、３４ｂ、３６ａ、３６ｂ、４６ａ、４６ｂ、４８ａ、４８ｂ、５０、５４…バルブ、４０…吸引ポンプ、４２ｘ〜４２ｚ…引き抜きダクト、４４ｘ〜４４ｚ…センサ部、５６…制御装置[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a gas processing method, and more particularly to a gas processing method for removing organic solvent components and malodorous components harmful to human bodies from exhaust gas in a manufacturing factory for manufacturing pharmaceuticals, semiconductors and the like.
[0002]
[Prior art]
In pharmaceutical manufacturing plants, there are processes for concentration and extraction of organic solvents, and exhaust gases emitted from these processes may contain organic solvent components and malodorous components (hereinafter collectively referred to as harmful components). . For this reason, in a pharmaceutical manufacturing plant, a gas processing facility for removing harmful components from exhaust gas is required.
[0003]
When the treatment amount of the exhaust gas is small, the gas treatment facility comprises a single adsorption tower filled with activated carbon, and the exhaust gas is introduced into this adsorption tower, and harmful components in the exhaust gas are adsorbed and removed by the activated carbon. In this gas processing facility, when activated carbon breaks through, the activated carbon is discarded and replaced with new activated carbon, or the broken activated carbon is handed over to a regeneration manufacturer and regenerated and exchanged off-site.
[0004]
On the other hand, when the exhaust gas treatment capacity is large, a plurality of adsorption towers are provided, and gas is introduced into at least one of the plurality of adsorption towers, and harmful components in the gas are adsorbed and removed. In this gas treatment facility, the exhaust tower is continuously treated by periodically switching the adsorption tower for introducing the gas and regenerating the activated carbon adsorbing the harmful components (that is, desorbing the harmful components). be able to.
[0005]
Gas treatment facilities comprising a plurality of adsorption towers are classified into a steam regeneration type and a dry regeneration type depending on the desorption method of activated carbon. The dry regeneration method is a method in which activated carbon is regenerated by passing the carrier gas heated by the heater through the adsorption tower to heat the activated carbon, or by directly heating the activated carbon with a heater installed in the activated carbon. is there. This method is easy to maintain, but has a drawback of low desorption efficiency.
[0006]
On the other hand, the steam regeneration type is a system in which steam is passed through an adsorption tower to uniformly heat activated carbon to perform desorption. Although this method has a very high desorption efficiency, it has a problem that the amount of steam used is large and a drainage treatment of drain generated when steam is supplied.
[0007]
Patent Document 1 describes a gas processing facility that decompresses the inside of an adsorption tower before supplying steam. According to this gas treatment facility, activated carbon can be regenerated only by introducing a small amount of steam, and the amount of steam used and the amount of wastewater treated can be reduced.
[0008]
[Patent Document 1]
JP-A-5-84417
[0009]
[Problems to be solved by the invention]
However, the conventional gas processing equipment has a possibility of supplying a large amount of excess steam because the switching of the adsorption tower is sequence control by a fixed timer. For example, when exhaust gas having a low concentration of harmful components is introduced into the adsorption tower, if the adsorption tower is periodically switched, the adsorption tower is switched in a state where the harmful components are not sufficiently adsorbed on the activated carbon. For this reason, steam is supplied to the activated carbon on which harmful components are not sufficiently adsorbed, and excess steam that does not contribute to the desorption treatment increases. Therefore, the conventional gas treatment equipment has a problem that the amount of wasteful steam supply increases and the wastewater treatment load increases.
[0010]
Furthermore, since the conventional gas processing equipment does not accurately know when to replace the activated carbon, the activated carbon having sufficient adsorption performance may be replaced.
[0011]
The present invention has been made in view of such circumstances, and an object of the present invention is to provide a gas processing method capable of reducing the amount of steam supplied and knowing the optimum replacement time of the adsorbent. .
[0012]
[Means for Solving the Problems]
In order to achieve the above object, the invention according to claim 1 allows the gas to pass through at least one of a plurality of adsorption towers in which adsorbents are stored, thereby reducing malodorous components and / or solvent components contained in the gas. In the gas treatment method of adsorbing the adsorbent and switching the adsorption tower through which the gas passes and desorbing the malodorous component and / or the solvent component adsorbed on the adsorbent, the gas adsorbed with the adsorbent, Alternatively, the concentration of the malodorous component and / or the concentration of the solvent component contained in the gas adsorbed with the adsorbent is measured, and the adsorption tower through which the gas passes is switched based on the measured value of the concentration. It is characterized by.
[0013]
According to the first aspect of the present invention, since the adsorption tower is switched based on the concentration of the malodorous component and / or the concentration of the solvent component contained in the gas after the adsorption treatment or during the adsorption treatment, the malodorous component and the solvent component are The desorption process is started in a state where the adsorbent is sufficiently adsorbed. Therefore, it is possible to reduce the amount of extra steam that does not contribute to the desorption process, and it is possible to reduce the amount of wastewater treatment that is necessary for the desorption process.
[0014]
In addition, according to the first aspect of the present invention, the adsorption tower is switched after the malodorous component and the solvent component are sufficiently adsorbed by the adsorbent, so that the time for the adsorption treatment is lengthened and the frequency of the desorption treatment is reduced. Therefore, the adsorption efficiency can be improved, the load on the adsorbent is reduced, and the life of the adsorbent is extended.
[0015]
In order to achieve the above-described object, the invention according to claim 2 allows the malodorous component and / or the solvent component contained in the gas to be passed by passing the gas through at least one of the plurality of adsorption towers containing the adsorbent. In the gas treatment method of adsorbing the adsorbent and switching the adsorption tower through which the gas passes and desorbing the malodorous component and / or the solvent component adsorbed on the adsorbent, the gas adsorbed with the adsorbent, Alternatively, the concentration of the malodorous component and / or the concentration of the solvent component contained in the gas adsorbed with the adsorbent is measured, and when the measured value of the concentration reaches a predetermined value, it is discharged from the adsorption tower. The flow path of the gas to be used is switched, and the gas is passed through an auxiliary adsorption tower.
[0016]
According to the second aspect of the present invention, when the concentration of the malodorous component and / or the concentration of the solvent component contained in the gas from the adsorption tower reaches a predetermined value, the gas flow path is switched and auxiliary adsorption is performed. Since the gas is allowed to pass through the tower, the gas whose concentration reaches a predetermined value is introduced into the auxiliary adsorption tower, and malodorous components and solvent components are removed by adsorption. Therefore, it is possible to prevent the gas having the concentration of the malodorous component or the solvent component from reaching a predetermined value.
[0017]
In order to achieve the above object, the invention according to claim 3 allows the malodorous component and / or the solvent component contained in the gas to be passed by passing the gas through at least one of the plurality of adsorption towers containing the adsorbent. In the gas treatment method of adsorbing to the adsorbent and switching the adsorption tower through which the gas passes and desorbing the malodorous component and / or the solvent component adsorbed on the adsorbent, before adsorbing with the adsorbent The concentration of the malodorous component contained in the gas and / or the concentration of the solvent component is measured, the time for the adsorption treatment with the adsorbent is calculated based on the concentration before the adsorption treatment, and based on the calculated value, The adsorption tower through which the gas passes is switched.
[0018]
According to the third aspect of the present invention, the adsorption tower is switched by calculating the adsorption treatment time based on the concentration of the malodorous component and / or the concentration of the solvent component contained in the gas before the adsorption treatment. In addition, the adsorption tower can be switched while the solvent component is sufficiently adsorbed by the adsorbent.
[0019]
The invention according to claim 4 is the invention according to claim 3, wherein the concentration of the malodorous component and / or the concentration of the solvent component contained in the gas adsorbed with the adsorbent or the gas adsorbed with the adsorbent. The density is measured, and the calculated value is corrected based on the density after the adsorption process or during the adsorption process. Therefore, according to the fourth aspect of the present invention, the calculation value is corrected according to the adsorbing state of the adsorbent, so that the optimal time for the adsorbing process can be obtained with high accuracy.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of a gas processing method according to the present invention will be described with reference to the accompanying drawings.
[0021]
FIG. 1 is a configuration diagram schematically showing a first embodiment of a gas processing facility to which a gas processing method according to the present invention is applied.
[0022]
As shown in FIG. 1, the gas processing apparatus 10 includes two towers of adsorption towers 12a and 12b. Support plates 16 and 16 are provided inside the adsorption towers 12a and 12b, and activated carbons 14a and 14b are filled on the support plates 16 and 16, respectively. As the activated carbons 14a and 14b, a fiber shape, a honeycomb shape, a pellet shape, or the like is arbitrarily selected. As the support plate 16, a member having air permeability and water permeability, such as a punching plate, is used.
[0023]
Introduction ducts 18 and 18 are connected to the upper portions of the adsorption towers 12a and 12b, respectively. The leading ends of the introduction ducts 18 and 18 are connected to a production facility, and the exhaust gas discharged from the production facility is introduced into the adsorption towers 12a and 12b via the introduction ducts 18 and 18. In the introduction ducts 18 and 18, dampers 20 a and 20 b are disposed at the introduction port portions of the respective adsorption towers 12 a and 12 b. By controlling the opening and closing of the dampers 20a and 20b, the adsorption towers 12a and 12b for introducing the exhaust gas are switched.
[0024]
In the gas introduced into the adsorption towers 12a and 12b, harmful components (bad odor components and / or solvent components) in the gas are adsorbed by the activated carbons 14a and 14b. And the process gas after adsorption | suction processing is derived | led-out from the extraction ducts 22 and 22 connected to the lower part of each adsorption tower 12a and 12b. The lead-out ducts 22 and 22 communicate with the outside air, and the gas led out from the adsorption towers 12a and 12b is released to the outside air through the lead-out ducts 22 and 22. Dampers 24a and 24b are disposed at the outlet ports of the adsorption towers 12a and 12b of the outlet ducts 22 and 22, respectively. The dampers 24a and 24b are controlled to be opened and closed together with the dampers 20a and 20b.
[0025]
Steam supply pipes 26 and 26 are connected to the lower portions of the adsorption towers 12a and 12b, respectively. The tips of the steam supply pipes 26 and 26 are connected to a steam generation source, and the steam generated from the steam generation source is supplied to the adsorption towers 12a and 12b via the steam supply pipes 26 and 26. Note that steam generated in a manufacturing facility may be used as a steam generation source.
[0026]
Valves 28a and 28b are disposed on the inlet side portions of the adsorption towers 12a and 12b of the steam supply pipes 26 and 26, respectively. By controlling the opening and closing of the valves 28a and 28b, steam is supplied to one of the adsorption towers 12a and 12b. The vapor supplied to the adsorption towers 12a and 12b is discharged from the vapor discharge pipes 30 and 30 connected to the upper portions of the respective adsorption towers 12a and 12b, or condensed into drains, and then the respective adsorption towers. Drain pipes 32 and 32 connected to the lower portions of 12a and 12b are discharged.
[0027]
The tips of the steam discharge pipes 30 and 30 are connected to a condenser, and the useful gas contained in the steam is collected by the condenser. On the other hand, the tips of the drain pipes 32, 32 are connected to a waste water treatment facility, and harmful components contained in the drain are removed. Valves 34a and 34b are disposed on the outlet sides of the adsorption towers 12a and 12b of the steam discharge pipes 30 and 30, respectively. Valves 36a and 36b are disposed on the outlet sides of the respective adsorption towers 12a and 12b of the drain pipes 32 and 32, respectively.
[0028]
Incidentally, the gas processing facility 10 is configured to measure the concentration of harmful components contained in the gas at three locations. That is, the gas processing facility 10 includes a suction pump 40 for extracting gas, first to third extraction ducts 42x, 42y, 42z connected to the suction port of the suction pump 40, and each extraction duct 42x, 42y, 42z. Sensor portions 44x, 44y, and 44z.
[0029]
Each of the sensor units 44x to 44z includes an odor sensor (not shown) that detects the concentration of malodorous components in the gas and a solvent sensor (not shown) that detects the concentration of the solvent components in the gas. Are connected in parallel. Therefore, the concentration of the malodorous component and the concentration of the solvent component in the gas flowing through the extraction ducts 42x to 42z can be simultaneously measured by the sensor units 44x to 44z.
[0030]
The first extraction duct 42x is connected to the adsorption towers 12a and 12b above the activated carbons 14a and 14b. Therefore, by driving the suction pump 40, the gas before the adsorption process is extracted. Further, valves 46a and 46b are provided in the first extraction duct 42x. When extracting the gas, the gas in the adsorption tower 12a or 12b is extracted by opening one of the valves 46a and 46b. The first extraction duct 42x may be connected to the introduction duct 18 and the gas flowing through the introduction duct 18 may be extracted.
[0031]
The 2nd extraction duct 42y is connected to the position of activated carbon 14a, 14b of each adsorption tower 12a, 12b. Therefore, the gas adsorbed by the activated carbons 14a and 14b is extracted. The second extraction duct 42y is provided with valves 48a and 48b. When extracting the gas, the gas is extracted from the adsorption tower 12a or 12b by opening one of the valves 48a and 48b. In addition, the connection position of the 2nd extraction duct 42y is the distance L from the upper end of activated carbon 14a, 14b to a connection position. ₁ However, the total height L of the activated carbon 14a, 14b ₀ It is preferable to set so that it may become 70 to 90%.
[0032]
The third extraction duct 42z is connected to the outlet duct 22. Accordingly, a part of the processing gas flowing through the outlet duct 22 is extracted to the third extraction duct 42z. Further, a valve 50 is disposed in the third extraction duct 42z, and by opening the valve 50, the processing gas is extracted and sucked into the suction pump 40.
[0033]
A return duct 52 is connected to the discharge port of the suction pump 40, and this return duct 52 is connected to the introduction duct 18. The return duct 52 is provided with a valve 54. By opening the valve 54, the gas sent from the suction pump 40 is returned to the introduction duct 18 through the return duct 52. Therefore, the gas extracted from the first to third extraction ducts 42x to 42z is reintroduced into the adsorption towers 12a and 12b, and harmful components are removed by adsorption.
[0034]
The dampers 20a, 20b, 24a, 24b and the valves 28a, 28b, 34a, 34b, 36a, 36b, 46a, 46b, 48a, 48b, 50, 54 described above are electrically connected to the control device 56. And is opened and closed by the control device 56.
[0035]
The control device 56 opens and closes the dampers 20a, 20b, 24a, and 24b to vent the exhaust gas to one of the adsorption towers 12a and 12b and perform the adsorption process. For example, by opening the dampers 20a and 24a and closing the dampers 20b and 24b, the exhaust gas is vented to the adsorption tower 12a, and the harmful components contained in the exhaust gas are adsorbed on the activated carbon 14a. Alternatively, by closing the dampers 20a and 24a and opening the dampers 20b and 24b, the exhaust gas is vented to the adsorption tower 12b, and harmful components contained in the exhaust gas are adsorbed on the activated carbon 14b.
[0036]
Further, the control device 56 opens and closes the valves 28a, 28b, 34a, 34b, 36a, and 36b, thereby venting steam to one of the adsorption towers 12a and 12b to perform the desorption process. For example, by closing the valves 28a, 34a, and 36a and opening the valves 28b, 34b, and 36b, steam is passed through the adsorption tower 12b, and harmful components adsorbed on the activated carbon 14b are desorbed. Alternatively, the valves 28a, 34a, and 36a are opened and the valves 28b, 34b, and 36b are closed, thereby venting the vapor to the adsorption tower 12a and desorbing harmful components adsorbed on the activated carbon 14a. The desorption process is performed in the adsorption towers 12a and 12b that are not performing the adsorption process. After the desorption process is completed, the valve 28a or 28b is closed and the adsorption towers 12a and 12b are made to stand by in a dry state.
[0037]
The control device 56 drives and controls the suction pump 40 and controls the valves 46a, 46b, 48a, 48b, 50, and 54 to open and close, thereby drawing the gas from the first to third drawing ducts 42x to 42z. At that time, the valves 46a, 46b, 48a, and 48b are opened and closed so as to extract gas from the adsorption tower 12a or 12b that is performing the adsorption treatment. And the density | concentration of the harmful | toxic component in gas is measured by the sensor parts 44x-44z arrange | positioned in the extraction ducts 42x-42z, Based on the measured value, the valve | bulb 20a, 20b, 24a, 24b mentioned above is opened and closed, and adsorption | suction The adsorption towers 12a and 12b to be processed are switched.
[0038]
Next, a method for controlling the gas processing facility 10 according to the first embodiment will be described.
[0039]
In the gas treatment facility 10, exhaust gas is passed through one adsorption tower 12a or 12b to perform adsorption treatment, and the other adsorption tower 12b or 12a performs desorption treatment. And when the measured value of the sensor part 44y provided in the 2nd extraction duct 42y reaches a predetermined value, it controls so that the adsorption towers 12a and 12b which perform adsorption processing are switched. Here, the predetermined value is set to a value stipulated by laws and regulations or a value lower than that, and is set for both the concentration of the malodorous component and the concentration of the solvent component. Then, switching control is performed when either the malodorous component concentration or the solvent component concentration reaches a predetermined value.
[0040]
When the measurement value of the sensor unit 44y reached a predetermined value when the adsorption process was performed in the adsorption tower 12a, the valves 20a and 24a were closed and the valves 20b and 24a were opened to ventilate the adsorption tower 12a. The exhaust gas is passed through the adsorption tower 12b. Similarly, if the measured value of the sensor unit 44y reaches a predetermined value when the adsorption process is performed in the adsorption tower 12b, the valves 20b and 24b are closed and the valves 20a and 24b are opened, so that the adsorption tower 12b is opened. The exhaust gas that has been ventilated is passed through the adsorption tower 12a.
[0041]
Next, the operation of the gas processing facility 10 configured as described above will be described.
[0042]
When the adsorption treatment is performed in the adsorption tower 12a or 12b, the concentration of harmful gas in the process gas derived from the adsorption tower 12a or 12b gradually increases with the elapsed time. That is, at the initial stage of the adsorption process, the activated carbons 14a and 14b have sufficient adsorption capacity, so that harmful components are reliably adsorbed on the activated carbons 14a and 14b. Accordingly, the concentration of harmful components contained in the processing gas discharged from the adsorption towers 12a and 12b is very low. However, as the adsorption process is performed, the adsorption ability of the activated carbons 14a and 14b gradually decreases, so that the concentration of harmful components in the process gas gradually increases. And when activated carbon 14a, 14b breaks through, the density | concentration of a harmful | toxic component will rise rapidly and will become a value close | similar to the density | concentration of the harmful | toxic component before adsorption | suction processing. In order to prevent this, conventionally, before the activated carbons 14a and 14b break through, the adsorption towers 12a and 12b are periodically switched to perform the adsorption treatment. For this reason, the adsorption towers 12a and 12b are switched in a state in which the activated carbons 14a and 14b do not sufficiently adsorb harmful components, and there is a problem that wasteful steam increases during the desorption process.
[0043]
In contrast, in the present embodiment, the adsorption towers 12a and 12b are switched when the measured value of the sensor unit 44y reaches a predetermined value. Therefore, since the adsorption towers 12a and 12b are switched in a state where harmful components are sufficiently adsorbed on the activated carbons 14a and 14b, the amount of useless steam that does not contribute to the desorption process when the desorption process is performed can be reduced.
[0044]
In the present embodiment, since the concentration of the harmful component is measured by extracting the gas during the adsorption process, it is possible to prevent the gas having the harmful component concentration reaching a predetermined value from being released. That is, when the concentration of harmful components reaches a predetermined value, the activated carbon 14a, 14b above the connection position of the extraction duct 42y is in a state close to breakthrough, but the activated carbon 14a, below the connection position, 14b has sufficient adsorption capacity. Therefore, since the harmful components are absorbed and removed by the activated carbons 14a and 14b below the connection position, the gas whose harmful component concentration has reached a predetermined value at the connection position is converted into a gas after passing through the activated carbons 14a and 14b. The concentration of the harmful component contained is lower than a predetermined value. Thereby, it is possible to prevent the gas whose harmful component concentration has reached a predetermined value from being released.
[0045]
Further, in this embodiment, the adsorption towers 12a and 12b are switched after the harmful components are sufficiently adsorbed on the activated carbons 14a and 14b, so that the time for performing the adsorption treatment is increased and the efficiency of the adsorption treatment can be improved. . Further, since the frequency of the desorption process is reduced, the load on the activated carbons 14a and 14b is reduced, and the life of the activated carbons 14a and 14b can be extended.
[0046]
Further, in the present embodiment, the time until the measured value of the sensor unit 44y reaches a predetermined value, that is, the time until immediately before the activated carbon 14a, 14b breaks through (hereinafter referred to as adsorption treatment time) is known. The replacement time of 14a and 14b can be predicted.
[0047]
In the first embodiment described above, the measured value of the sensor unit 44x may be used to calculate the time for the adsorption process. Then, the production process may be managed based on the calculated time, or the concentration may be measured by extracting gas only before and after the calculated time.
[0048]
Furthermore, in the second embodiment described above, the measured value of the sensor unit 44z may be used for detecting an abnormality. For example, if an abnormal situation occurs when the measured value of the sensor unit 44z reaches the predetermined value described above, it is preferable to warn an operator or stop the apparatus.
[0049]
FIG. 2 is a configuration diagram schematically showing a second embodiment of the gas processing facility according to the present invention.
[0050]
As shown in FIG. 2, in the gas processing facility of the second embodiment, a damper 60 is disposed at the tip of the outlet duct 22, and a bypass line 62 is connected to the upstream side and the downstream side of the damper 60. ing. A damper 64 and an auxiliary adsorption tower 66 are disposed in the bypass line 62. The auxiliary adsorption tower 66 is configured in the same manner as the adsorption towers 12a and 12b, and is filled with activated carbon 68 inside. However, the auxiliary adsorption tower 66 has a smaller capacity than the adsorption towers 12a and 12b.
[0051]
In the second embodiment configured as described above, when the adsorption process is performed in the adsorption tower 12a or 12b, the damper 60 is opened and the damper 64 is closed. When the measured value of the sensor unit 44z reaches a predetermined value, the adsorption towers 12a and 12b for performing the adsorption process are switched, the damper 60 is closed, and the damper 64 is opened. As a result, the processing gas flowing through the outlet duct 22 flows into the bypass line 62 and is introduced into the auxiliary adsorption tower 66. In the processing gas introduced into the auxiliary adsorption tower 66, harmful components are adsorbed by the activated carbon 68. Therefore, the concentration of harmful components in the processing gas discharged from the auxiliary adsorption tower 66 is lower than a predetermined value. Thereby, when the adsorption towers 12a and 12b are switched, it is possible to prevent the release of the gas whose harmful component concentration has reached a predetermined value.
[0052]
The time for passing the processing gas through the auxiliary adsorption tower 66 may be about several minutes or several tens of seconds. Alternatively, after confirming that the measured value of the sensor unit 44z has sufficiently decreased, the ventilation to the auxiliary adsorption tower 66 may be stopped.
[0053]
Further, the desorption process may be performed by supplying steam to the auxiliary adsorption tower 66 in which the flow of the processing gas is stopped.
[0054]
Furthermore, in the second embodiment described above, the adsorption towers 12a and 12b are switched based on the measured value of the sensor unit 44z. However, the present invention is not limited to this, and the sensor unit 44y is similar to the first embodiment. You may switch based on a measured value. In this case, the gas whose harmful component concentration has reached a predetermined value is adsorbed by the activated carbons 14a and 14b below the connection position of the extraction duct 42y and the activated carbon 68 of the auxiliary adsorption tower 66. It is possible to prevent the processing gas having a high component concentration from being released.
[0055]
FIG. 3 is a control system diagram of the gas processing facility according to the third embodiment. In addition, the gas processing equipment of 3rd Embodiment is comprised similarly to the gas processing equipment 10 of 1st Embodiment shown in FIG.
[0056]
As shown in FIG. 3, the control device 56 includes a database 70, an arithmetic processing unit 72, and a damper / valve control unit 74. Data of measurement values of the sensor units 44 x and 44 y and production information from the control unit 76 of the manufacturing facility are input to the arithmetic processing unit 72. As the production information, for example, the type and amount of gas used in the manufacturing facility, the operating time and the number of operating lines of the manufacturing facility, the type of product and the production amount, and the like are input.
[0057]
Based on the measurement values and production information of the sensor units 44 x and 44 y and the calculation method stored in the database 70, the calculation processing unit 72 performs adsorption processing time (time until immediately before the activated carbons 14 a and 14 b in FIG. 1 break through). ) Is calculated. Data related to this calculation (data such as measurement values, production information, and the number of calculations) is stored in the database 70, and a neuro network is constructed. Thereby, the accuracy of the calculation of the suction processing time can be increased as the number of times of the arithmetic processing increases.
[0058]
Data indicating the result calculated by the arithmetic processing unit 72 is output to the damper / valve control unit 74. The damper / valve controller 74 opens and closes the dampers 20a, 20b, 24a, 24b and the valves 28a, 28b, 34a, 34b, 36a, 36b, 46a, 46b, 48a, 48b, 50, 54 based on the calculation result. That is, the adsorption towers 12a and 12b are switched in the calculated adsorption treatment time.
[0059]
Next, the operation of the gas processing facility of the third embodiment configured as described above will be described.
[0060]
Since the state of the exhaust gas introduced into the adsorption towers 12a and 12b, that is, the flow rate of the exhaust gas and the type and concentration of harmful components contained in the exhaust gas are not always constant, immediately before the activated carbons 14a and 14b break through. The adsorption treatment time up to is not always constant and may change greatly. In addition, even when the state of the exhaust gas is constant, as the desorption process is repeated, the adsorption performance of the activated carbons 14a and 14b after the desorption process gradually decreases, so that the adsorption process time gradually decreases. is there.
[0061]
In order to solve such a problem, in the third embodiment, the state of the exhaust gas before being introduced into the adsorption towers 12a and 12b is input by inputting the measurement value and production information of the sensor unit 44x to the arithmetic processing unit 72. The adsorption processing time is calculated based on the accurate grasp. Therefore, even if the state of the exhaust gas changes, the adsorption towers 12a and 12b can be switched at the optimum timing, that is, at the timing when the adsorbents 14a and 14b sufficiently adsorb harmful components.
[0062]
In the third embodiment, since the measurement value of the sensor unit 44y is input, the actual adsorption capacity of the adsorbents 14a and 14b can be known, and the calculation result can be corrected based on this. The adsorption processing time can be obtained accurately.
[0063]
Furthermore, in the third embodiment, by accumulating data for each number of times of adsorption processing in the database 70, it is possible to accurately obtain the adsorption processing time that gradually decreases. Therefore, an optimum adsorption processing time can always be calculated even for an adsorbent having a large number of adsorption processes and desorption processes. Moreover, the optimal replacement | exchange time of activated carbon 14a, 14b can be estimated from this calculation result.
[0064]
In addition, although the 1st-3rd embodiment mentioned above used the two adsorption towers 12a and 12b, you may use three or more adsorption towers. At that time, the adsorption treatment may be performed in at least one adsorption tower.
[0065]
Moreover, although embodiment mentioned above used activated carbon as an adsorbent, the kind of adsorbent is not limited to this, For example, according to the target object to adsorb | suck adsorbents, such as activated alumina, a silica gel, and a zeolite. You may choose.
[0066]
Furthermore, although embodiment mentioned above provided the odor sensor which measures the density | concentration of a malodorous component, and the solvent sensor which measures the density | concentration of a solvent component as sensor part 44x-44z, either one of a malodorous component and a solvent component is provided. When removing only a component as a target, only a sensor for the target component needs to be provided.
[0067]
【The invention's effect】
As described above, according to the gas treatment method of the present invention, the adsorption tower for performing the adsorption treatment based on the concentration of the malodorous component and / or the concentration of the solvent component contained in the gas after the adsorption treatment or during the adsorption treatment. Since the switching is performed, the desorption process can be started in a state where the harmful components are sufficiently adsorbed on the adsorbent. As a result, it is possible to reduce the amount of useless steam that does not contribute to the desorption treatment, and as a result, it is possible to reduce the amount of steam supply and the amount of wastewater treatment.
[0068]
In addition, according to the gas treatment method of the present invention, when the adsorption tower is switched, the gas is vented to the auxiliary adsorption tower, so that it is possible to prevent the gas whose concentration has reached a predetermined value from being released. .
[0069]
Furthermore, according to the gas treatment method of the present invention, the adsorption treatment time is calculated based on the concentration of malodorous components and / or the concentration of the solvent component contained in the gas before the adsorption treatment, and the adsorption tower is switched. The adsorption tower can be switched at the timing.
[Brief description of the drawings]
FIG. 1 is a configuration diagram schematically showing a first embodiment of a gas processing facility to which a gas processing method according to the present invention is applied.
FIG. 2 is a configuration diagram schematically showing a characteristic part of a gas processing facility according to a second embodiment.
FIG. 3 is a control system diagram of a gas processing facility according to a third embodiment.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Gas processing equipment, 12a, 12b ... Adsorption tower, 14a, 14b ... Activated carbon, 18 ... Introduction duct, 22 ... Outlet duct, 20a, 20b, 24a, 24b ... Damper, 26 ... Steam supply pipe, 30 ... Steam discharge pipe 32 ... Drain pipe, 28a, 28b, 34a, 34b, 36a, 36b, 46a, 46b, 48a, 48b, 50, 54 ... Valve, 40 ... Suction pump, 42x-42z ... Extraction duct, 44x-44z ... Sensor part 56 ... Control device

Claims

An adsorbing tower for adsorbing malodorous components and / or solvent components contained in the gas to the adsorbing material by allowing the gas to pass through at least one of a plurality of adsorbing towers containing the adsorbing material, and allowing the gas to pass therethrough. In the gas treatment method of switching and desorbing the malodorous component and / or the solvent component adsorbed on the adsorbent,
Measure the concentration of the malodorous component and / or the concentration of the solvent component contained in the gas adsorbed with the adsorbent or the gas adsorbed with the adsorbent,
A gas processing method, wherein an adsorption tower through which the gas passes is switched based on a measured value of the concentration.

An adsorbing tower for adsorbing malodorous components and / or solvent components contained in the gas to the adsorbing material by allowing the gas to pass through at least one of a plurality of adsorbing towers containing the adsorbing material, and allowing the gas to pass therethrough. In the gas treatment method of switching and desorbing the malodorous component and / or the solvent component adsorbed on the adsorbent,
Measure the concentration of the malodorous component and / or the concentration of the solvent component contained in the gas adsorbed with the adsorbent or the gas adsorbed with the adsorbent,
When the measured value of the concentration reaches a predetermined value, the gas processing method is characterized in that the flow path of the gas discharged from the adsorption tower is switched and the gas is passed through the auxiliary adsorption tower.

An adsorbing tower for adsorbing malodorous components and / or solvent components contained in the gas to the adsorbing material by allowing the gas to pass through at least one of a plurality of adsorbing towers containing the adsorbing material, and allowing the gas to pass therethrough. In the gas treatment method of switching and desorbing the malodorous component and / or the solvent component adsorbed on the adsorbent,
Measure the concentration of the malodorous component and / or the concentration of the solvent component contained in the gas before the adsorption treatment with the adsorbent,
Based on the concentration before the adsorption treatment, the time for the adsorption treatment with the adsorbent is calculated,
A gas processing method characterized by switching an adsorption tower through which the gas passes based on the calculated value.

Measure the concentration of the malodorous component and / or the concentration of the solvent component contained in the gas adsorbed with the adsorbent or the gas adsorbed with the adsorbent,
The gas processing method according to claim 3, wherein the calculated value is corrected based on a concentration after the adsorption process or during the adsorption process.